Gas turbine support element permitting thermal expansion between combustor shell and rotor cover at turbine inlet

Abstract

A gas turbine includes a compressor, an annular combustion chamber, and a turbine, a combustion chamber shell of the combustion chamber adjoining the turbine inlet in a transition region in order to introduce the hot gases generated in the combustion chamber into the downstream turbine such that a thermal expansion-induced relative movement between the combustion chamber and the turbine inlet is possible. Combustion chamber shell support elements distributed on the periphery come into contact with a conical contour on the shaft cover due to the thermal expansion that occurs during operation and are supported on said contour. An improvement with respect to loading and service life is achieved in that the conical contour and the machine axis form an angle that allows the combustion chamber shell support elements to slide onto the conical contour.

The invention claimed is: 
     
       1. A gas turbine, comprising: a combustor comprising a combustor shell and a combustor outlet; a turbine disposed downstream of the combustor, the turbine comprising an inlet separated from the combustor outlet by a transition region, the transition region defining a gap between the combustor and the turbine; and a plurality of support elements fixedly attached along an inner circumference of the combustor shell, each support element comprising a pivot bearing configured to support a pivotable transition element that extends in a direction away from the support element and is configured to movably bridge the gap defined by the transition region between the combustor and the turbine; wherein a rotor cover of the gas turbine defines a conical contour surface that is configured to slideably engage a bevel surface portion of each support element upon thermal expansion of the combustor shell; and further comprising a pressure bolt acted on by a compression spring that is configured to press a free end of the pivotable transition element against a wall of the inlet of the turbine, another end of the pivotable transition element being coupled to the pivot bearing. 
     
     
       2. The gas turbine as claimed in  claim 1 , wherein each support elements comprises a radially projecting, axially oriented support plates or fins, and wherein the bevel surface portion of the support element is opposite the inner circumference of the combustor shell and the bevel surface portion being complementary to the conical contour surface of the rotor cover, and wherein a non-zero installation tolerance is provided between the conical contour surface and the bevel surface portion. 
     
     
       3. The gas turbine as claimed in  claim 2 , wherein thermal expansion of the combustion shell occurs in an expansion direction towards the conical contour surface of the rotor cover, and wherein an angle defined by the expansion direction relative to the conical contour surface is a non-zero differential angle. 
     
     
       4. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle defined by the expansion direction relative to the contour surface of the rotor cover is in the range between 2° and 15°, and an angle defined by the bevel surface portion of the support element and a machine axis is between 20° and 30°. 
     
     
       5. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle is in the range between 2° and 15°, and the angle defined by the bevel surface portion of the support element relative to the machine axis is between 24° and 26°. 
     
     
       6. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle is in the range between 5° and 10°, and the angle defined by the bevel surface portion of the support element relative to the machine axis is between 20° and 30°. 
     
     
       7. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle is in the range between 5° and 10°, and the angle; defined by the bevel surface portion of the support element relative to the machine axis enclose is between 24° and 26°. 
     
     
       8. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle is in the range between 7° and 8°, and the angle defined by the bevel surface portion of the support element relative to the machine axis is between 20° and 30°. 
     
     
       9. The gas turbine as claimed in  claim 3 , wherein the non-zero differential angle is in the range between 7° and 8°, and the angle; defined by the bevel surface portion of the support element relative to is between 24° and 26°. 
     
     
       10. The gas turbine as claimed in  claim 2 , wherein the installation tolerance is in the range between 1 millimeters (mm) and 10 mm. 
     
     
       11. The gas turbine as claimed in  claim 2 , wherein the installation tolerance is in the range between 2 millimeters (mm) and 8 mm. 
     
     
       12. The gas turbine as claimed in  claim 2 , wherein the installation tolerance is in the range between 3 millimeters (mm) and 4 mm. 
     
     
       13. The gas turbine as claimed in  claim 1 , wherein the rotor cover is made of gray cast iron and the plurality of support elements consist of a nickel-based alloy or an 18/10-Cr—Ni steel. 
     
     
       14. The gas turbine as claimed in  claim 1 , wherein the combustor shell is composed of individual segments, and wherein two support elements of the plurality of support elements are provided per individual segment. 
     
     
       15. The gas turbine as claimed in  claim 1 , wherein a first end of the pivotable transition element is coupled to the pivot bearing and a second end of the pivotable transition element is configured to be pressed against a wall of the inlet of the turbine to bridge the gap defined by the transition region between the combustor and the turbine. 
     
     
       16. The gas turbine according to  claim 1  wherein the bevel surface portion of the support element is configured to slide against the conical contour surface of the rotor during thermal expansion and contraction of the combustor shell. 
     
     
       17. The gas turbine according to  claim 1  wherein the thermal expansion of the combustor shell causes a movement of the support plate towards the conical contour surface of the rotor cover and a rotation of the pivotable transition element about the pivot bearing towards a wall of the inlet of the turbine. 
     
     
       18. A combustor inner shell for a gas turbine comprising, at an outlet end, on a side facing away from hot gases produced by the gas turbine, a plurality of support elements distributed on a periphery of the combustor inner shell and wherein each support element comprises a bevel surface portion, the bevel surface portion for sliding over a rotor cover conical contour surface during thermal expansion of the combustor inner shell, which defines an angle relative to a machine axis of the gas turbine, and a pivot bearing that supports a pivotable transition element, the pivotable transition element comprising a first end coupled to the pivot bearing and a second unattached end that extends towards the outlet end of the combustor inner shell, and further comprising a pressure bolt acted on by a compression spring that is configured to press the second unattached end of the pivotable transition element against a wall of an inlet of a turbine. 
     
     
       19. A gas turbine comprising a rotor cover, a combustor shell and a turbine inlet,
 wherein the rotor cover comprises, at a downstream end, on an outer side, a conical contour surface portion; 
 wherein the combustor shell comprises a plurality of support elements disposed along a wall of the combustor shell, each support element having a bevel surface portion; wherein each support element further comprises a pivot bearing that is configured to pivotally support a first end of a plate shaped pivotable transition element; 
 wherein the turbine inlet comprises a wall; 
 wherein a second end of the plate shaped pivotable transition element is configured to be pressed against the wall of the turbine inlet by a pressure bolt acted on by a compression spring;
 and wherein the bevel portion of each support element is configured to slide over the conical contour surface portion of the rotor cover during thermal expansion and contraction of the combustor shell.